Congenital junctional ectopic tachycardia and congenital complete atrioventricular block: A shared etiology?

Abstract

t c a U o d Congenital junctional ectopic tachycardia is a rare but erious arrhythmia with onset in infancy and early childood. Its etiology is poorly understood. Henneveld et al escribed a patient with congenital junctional ectopic tachyardia who subsequently developed complete atrioventriclar block. Histologic studies of congenital junctional ecopic tachycardia suggest an association with fibrosis of the V node. These observations suggest a relationship between conenital junctional ectopic tachycardia and congenital comlete atrioventricular block. Similar to congenital junctional ctopic tachycardia, congenital complete AV block is an rrhythmia of infancy and is associated with extensive firosis of the AV node. In children with structurally normal hearts, congenital omplete AV block is most commonly associated with maernal connective tissue disease, manifested by the presence f maternal anti-SSA and anti-SSB antibodies. Studies in nimals and in humans suggest anti-SSA and anti-SSB ntibodies have a direct effect on the conduction system in etuses and neonates. We hypothesized that congenital junctional ectopic achycardia is caused by anti-SSA and anti-SSB antibodies. n this report, we present evidence from three families in upport of this hypothesis. Two families were diagnosed ostnatally, whereas one child was diagnosed in utero using etal magnetocardiography. Congenital junctional ectopic achycardia was diagnosed by ECG or fetal magnetocardioraphy when a narrow QRS complex tachycardia with AV issociation and an atrial rate slower than the ventricular ate was seen. Patients and their mothers were tested for nti-SSA and anti-SSB antibodies by enzyme-linked immuosorbent assay at commercial laboratories (Associated Reional and University Pathologists, SmithKline Beecham,